The Nominal System

This chapter is the foundation of every other chapter. Arabic grammar revolves around two engines: the noun (الاسم) and the verb (الفعل). This chapter is the noun engine — what nouns are, what shapes they take, and how to read the tiny vowel marks at their ends (iʿrāb) that tell you their job in a sentence.

If you come from English, three things will feel new:

• Number is three, not two. Arabic has a dual (مثنى) for exactly two of anything — a separate form, not just "two + plural".
• Case still matters. The ending of a noun changes depending on whether it is subject, object, or governed by a preposition. English lost most of this; Arabic kept all of it.
• Some words never change. A whole class of words (pronouns, demonstratives, most relatives and interrogatives) are mabnī ("built/fixed") — their shape never changes regardless of their role. You parse them by what slot they occupy, not by their ending.

Master those three ideas and the rest of the chapter is detail.

The dual is the single biggest mental shift here. In English we say "two boys" using "two" + plural. In Arabic, "two" is baked into the shape of the noun. The plural أَوْلَاد (boys) is reserved for three or more. For exactly two, you say وَلَدَانِ.

Just as important: that dual ending flips depending on the case:

• Subject / nominative (مَرْفُوع): جاء الولدانِ — "The two boys came."
• Object / accusative (مَنْصُوب): رأيتُ الولدَيْنِ — "I saw the two boys."
• After a preposition / genitive (مَجْرُور): سلّمتُ على الولدَيْنِ — "I greeted the two boys."

The "dependents of the dual" (كلاهما, اثنان, etc.) aren't dual in form, but they inflect as if they were — examiners love testing this.

The labels can mislead you. "Sound" (سالم) means the singular survives intact: مُعَلِّم → مُعَلِّمُونَ. "Broken" (تكسير) means the singular is shattered and re-arranged: كِتَاب → كُتُب. It's exactly like English's "mouse → mice" vs. "book → books", except Arabic uses dozens of broken-plural patterns, not just two or three.

Two traps to avoid:

• "Sound masculine" is gender-restricted. You can't form it from inanimate nouns; قَلَم ("pen") doesn't become قَلَمُون — it goes broken: أَقْلَام.
• Broken plurals of non-sentient nouns take singular feminine agreement. "The books are useful" is الكُتُبُ مُفِيدَةٌ, not مُفِيدُونَ. This rule kills careless writers in Paper 1.

Spend serious time memorising the broken-plural pattern of every noun you learn. There is no shortcut and no fully reliable rule. Lists like فِعَال · أَفْعَال · فُعُول · فُعَلَاء · أَفَاعِيل are the price of admission.

Here is the cleanest way to think about it:

• Indefiniteness is shown by tanwīn — the doubled vowel mark on the last consonant: ـٌ (-un, nom.), ـً (-an, acc.), ـٍ (-in, gen.). That doubled mark is the closest equivalent to English "a/an".
• Definiteness has seven flavours, not one. الـ is only one of them. A noun is also definite if it is a proper name, a pronoun, a demonstrative, a relative, possessive (كتابي), or a vocative (يا رجل) — see Topic 4.
• You can't have both. A word with الـ never has tanwīn; a word with tanwīn never has الـ. This is the single most common spelling error English learners make.

And one subtle point: definiteness drives agreement. An adjective modifying a definite noun must also be definite (الكتابُ الجديدُ); modifying an indefinite, it stays indefinite (كتابٌ جديدٌ).

Two of these will surprise you:

• Possessive construction (الإضافة) is definite. In كتابُ الطالبِ ("the student's book"), the word كتاب has no الـ — yet it is definite, because it has been "added" to the definite الطالبِ. Putting الـ on the first word would be an error (×الكتابُ الطالبِ).
• The vocative makes the noun definite. يا رجل ("O man!") refers to a specific addressee — and crucially, vocative nouns are built on the ḍamma with no tanwīn.

When parsing a noun, your first question should always be: is it definite, and if so, by which of the seven means? That single question solves half the comprehension questions on Paper 1.

These four categories exist because weak letters at the end of a word fight back against the vowels we want to put on them. Arabic responds by either implying the vowel or dropping the letter — the rules in the table above. As a learner, the practical takeaways are:

• If a noun ends in ى or ا (no visible vowel afterwards), you almost certainly cannot show its case visibly — you write "its case is implied" (مقدّر) in your parsing.
• If a noun looks like قاضٍ (with that little hook of tanwīn kasr and no ي), don't be tricked — its full form is قاضي; the ي has been dropped because the noun is indefinite, nominative or genitive.
• The accusative is where the ي reappears: رأيتُ قاضيًا ("I saw a judge"). Memorise this as a single example.

This is the most important pair in Arabic grammar to internalise. Every time you parse a noun, your second question (after "is it definite?") must be: is it muʿrab or mabnī?

• If muʿrab — write its case (nominative / accusative / genitive) and the visible sign of that case.
• If mabnī — write what it is "built on" (e.g. "built on the fatḥa") and, separately, the case-slot it occupies ("in the position of nominative subject").

Example: in هذا الكتابُ مفيدٌ, the word هذا is built on the sukūn (its shape never changes) but occupies the position of nominative subject (مبتدأ). You parse both facts.

Two duals are tricky exceptions. The duals of demonstratives and relatives (هذانِ / هذينِ, اللذانِ / اللذينِ) are declined like ordinary duals. Don't list them with the mabnī set.

This is the most important section of Chapter 1 — and the most painful for English speakers. Three habits will save you:

• Always identify the type before parsing. Is the pronoun detached (هو · هي · أنا), attached (ـه · ـها · ـتُ · ـنا · ـك), or hidden? The same job (e.g. "subject") gets a very differently worded parsing for each type.
• Pronouns are always مبنية. Their shape never changes. Don't try to find iʿrāb on them — find the slot they fill, and call them "built-pronoun in the position of [role]". The Arabic formula is ضمير مبنيّ … في محلِّ [رفع/نصب/جر] ….
• The default subject of a present-tense verb is a hidden pronoun. In يكتبُ الولدُ the subject is الولد; but in الولدُ يكتبُ the subject of يكتب is a hidden هو, and الولدُ is the mubtadaʾ. This shift trips up almost every Paper 1 candidate.

English has only two demonstratives ("this/these" near, "that/those" far). Arabic has many more because it pre-encodes gender, number, and proximity. The most common mistake is forgetting that demonstratives must agree with the noun they point to in both gender and number — and that, for non-sentient plurals, the demonstrative shifts to feminine singular (هذه الكتبُ, not هؤلاء الكتبُ).

The badal-vs-khabar split (point 3 above) is also worth memorising: it determines whether your sentence ends with a full predication ("this is X") or just sets up a phrase ("this X is Y").

The ṣila-clause is the foreign idea here. In English, "the man who came" makes "who came" function as a relative clause modifying "the man". In Arabic, the relative noun (الذي) is itself the head; the clause that follows is its ṣila, and it must contain a returning pronoun (ʿāʾid) referring back to the relative:

• جاءَ الذي رأيتُه أمس — "The one whom I saw yesterday came." The returning pronoun is the ـه attached to رأيت.
• قرأتُ الكتابَ الذي اشتريتُه — "I read the book that I bought." The returning pronoun is in اشتريته.

If the returning pronoun is dropped in your writing, the sentence is grammatically broken — examiners flag this every year.

Note also that مَنْ ("who/whoever") and ما ("what/whatever") are general relatives — they don't agree in gender or number, just in sentience.

Two genuine surprises:

• "Yes" and "no" map oddly to negative questions. If someone asks أليس محمدٌ هنا؟ ("Isn't Muhammad here?") and Muhammad is here, you say بلى — not نعم. نعم would confirm the negative ("Yes — he is not here"). English collapses both into "yes"; Arabic forces you to clarify.
• ماذا ≠ ما exactly. Both translate as "what", but ماذا is for asking what someone did (verb context) and is often parsed as ما + ذا; ما alone is more typical with nominal questions (ما اسمُك؟).

This single table is the entire mechanical core of Arabic grammar. Memorise it. If you can answer "what sign does X take for case Y?" for any word, you are ahead of 90% of candidates.

A workable mental map:

• The default trio is ḍamma / fatḥa / kasra — the visible vowel marks for nominative / accusative / genitive.
• Sub-marks kick in for "structured" categories — dual, sound masculine plural, Five Nouns, Five Verbs, diptotes. Each has its own substitute letter or vowel.
• Implied marks kick in for "weak-ending" words — maqṣūr, manqūṣ, possessives ending in yāʾ-of-the-speaker, weak-ending present verbs.

When you parse, your answer should always state both the case and the specific sign that shows it. "Accusative" is half a parse; "accusative with the sub-mark yāʾ because it is dual" is a full parse.

The book ends Chapter 1 with a small grid of frequent spelling mistakes. The correct forms are on the right:

English-speaking learners almost always slip on the first two — the soft inserted yāʾ in أنتي and the redundant alif in هاذا reflect how the word sounds rather than how it's spelled.